Institute of Anatomy, 2nd and 1st Medical Faculty. R. Druga

Institute of Anatomy, 2nd and 1st Medical Faculty R. Druga

MOZEČEK Anatomický ústav 2.a 1. LF R. Druga

Little brain

Cerebellar gyri = folia Cortex, subcortical white matter, nuclei, Kůra, bílá hmota, jádra Excessive folding of the cerebellar surface (cortex) Mimořádně bohatá gyrifikace kůry

Little brain Located in the posterior crerebral fossa Connected with the brain stem- by peduncles (inferior, middle, superior) Is covered by the cerebellar cortex (3 layers). Cortex is extensively folded (folia-oriented mediolaterally) White matter fibers going to and coming from the cortex In the white matter are the cerebellar nuclei

MR examination Fossa cranii posterior Posterior cranial fossa

Arterial supply SCA AICA PICA

Weigert Staining Myelinizovaná vlákna White matter has a treelike appearance = arbor vitae ( tree of life )

Klüver Barrera staining Folia are not interupted Folia jsou nepřerušena Cerebellar hemispheres and vermis

Unfolded surface of the cerebellum Rozvinutá kůra do plochy (dvourozměrná rekonstrukce) Breadth = 10 15 cm Šířka = 10 15 cm Délka = 1 mm

Anterior lobe (I V lobules) Posterior lobe (VI IX lobules) Flocculo-nodular lobe (lobule X)

Deep Fissures Fissury

VII B boundary between superior and inferior surface

Cerebellar Longitudinal zones lobes and a) Vermis (worm) Lobuli c) Lateral portion I X Lobi a Lobuli I-X b) Paravermal zone

CEREBELLAR NUCLEI, neurons glutamatergic, excitatory, high spontaneous activity Mozečková jádra, glutamátergní neurony, vysoká spontánní aktivita

J.E. Purkyně 1837 Wroclaw, Poland Breslau, Silesia Purkyně s original lithography (engraving) Purkyně observed for the first time large cells of the cerebellar cortex

R. y Cajal : Histologie du systeme nerveux, 1911.

Santiago Ramon y Cajal 1911 (Cajal confirmed Purkyně s findings)

Basket cells, inhibitory interneurons, GABAergic

Kompletní dendritická arborizace Purkyňovy b.

Climbing Fibers Šplhavá vlákna Olivocerebellar projections (crossed)

Hematoxilin- Eosin 1st 1stlayer 3rd layer

Synaptophysine immunostaining (pozitivita na synaptických kontaktech) Image265. x4 s ynapto Š varc

Image267.t4 x10

Image272 x20

Two types of afferent fibers Dva typy aferentních vláken Šplhavá vlákna inferior olive Mechová vlákna spinal cord, brain stem (trigeminal ncc., vestibular ncc., RF, pontine ncc.)

Purkyně cell and climbing fibre INFERIOR OLIVE

Terminals of the mossy fibers (cerebellar glomerulus rosetta) Zakončení mechového vlákna v granulární vrstvě (kontakt s dendrity několika granulárních buněk) One mossy fiber has excitatory contacts with several granular cells

Mossy fiber Mechová vlákna Granular cells Paralel fibers Purkyně cells dendrites Excitatíon of P. cells = inhibition of cerebellar nuclei

RED = inhibition Červená = inhibice Černá = excitace BLACK = excitation

J. Eccles 1967 Nobel Prize in Physiology and medicine 1963

Mossy fibers Climbing Granule cells- fiber Paralel fibers Purkyně cells Purkyně cell

Tracts : Mossy fibers Vestibulocerebellar (from the labyrinth and vestibular nuclei) Spinocerebellar ant., post., rostral, cuneocerebellar Reticulocerebellar Nucleocerebellar Pontocerebelar!! (cortico-pontocerebellar) Climbing fibers Olivocerebellar fibers Corticonuclear (from the cerebellar cortex to the nuclei) Vermis nc. fastigii Paravermal zone nc. embol. Nc. glob. Lateral hemisphere nc. dentatus From cerebellar nuclei to the brain stem and to the thalamus

Spinocerebellar Pathways Posterior T1 L2, uncrossed ICP, proprioceptors Anterior L3 L5 Crossed, SCP, cutaneous signals Rostral C4 C8 Uncrossed, ICP Cutaneous signals Cuneocerebellar C2 T4 uncrossed Lateral cuneate nc., propriocept. ICP

FMI areas of increased blood flow during flexion and extension of ipsilateral hand (red, orange) and foot (blue) Somatotopy in the cerebellar cortex

Afferent projections

Cortico- pontine pathway 17 millions fibers Neocortex ipsilat. pontine ncc. pontocerebellar pathway contralateral cerebellar cortex (mossy fibers) Cortex ncc. Pontis Mozečková kůra

Cortico ponto cerebellar pathway (monkey)

Climbing fibers Šplhavá vlákna Olivocerebellární projekce Inferior olive

Climbing fibers inferior olive (each P.cell receives only 1 c.f., many synapses with P.c.), excitatory (glutamate), firing frequency of the c.f. is very low (1 impulse/sec), c.f. elicit burst of action potentials in the P.c. C.f. inform about errors in the execution of movements error indicators!!

Mossy fibers - spinal cord, RF, pontine nuclei, ncc. cranial nerves. End in the granular layer and each of which contacts large number of granular neurons. Granular cell axon contacts large number of P. c. via paralel fibers. Mossy fibers are excitatory (glutamate). Each mossy fiber influences many P.c. but the excitatory effect is weak. Many mossy fibers must be active together to provide sufficient excitation to fire a P.c. Mossy fibers provide precisely graded information about movements, skin stimulations, joint position and about motor comands issued from the cerebral cortex.

Kortikonukleární projekce

Fastigial nucleus vestibular nuclei, reticular formation Emboliformis + globosus nucleus -.reticular formation, nc. ruber, thalamus Nucleus dentatus nc. ruber, contralateral thalamus (ventrolateral nucleus, intralaminar thalamic nuclei, ventral anterior nc., Ventrolateral nucleus primary motor cortex (area 4)

Dentato-thalamic projection (V. Chan-Palay)

Thalamus Nc. Ventralis Lateralis Nc. VL Motor cortex V. Chan-Palay

V. Chan-Palay : Cerebellar cortex Dentate nucleus

Corticopontocerebellocortical circuit 1 neocortex 3- pontine ncc. 5 cerebellar ncc. 8 thalamus (VL) (Transcerebellar Circuit) 3x

Mozečkové syndromy Flokulonodulární sy poruchy rovnováhy, nejistota při chůzi a stoji, nystagmus Sy předního laloku nejistá chůze (ataxie, zejména při lézi vermis a paravermální oblasti), alkohol Neocerebellární sy koordinace volních pohybů, poh\b\ nejisté, trhané, neplynulé, dekomposice pohybů, dysmetrie (pohyb není včas zastaven) dysdiadochokinesa, intenční třes, mozečková řeč, Kognitivní funkce

Paleocerebellar lesions (syndrome)

S. R. y Cajal : Histologie du systeme nerveaux, Malone, 1911 P. Kopf-Meier : Atlas of human anatomy, Karger, 2000. J.H. Martin : Neuroanatomy, McGraw-Hill, 2003 V. Chan-Palay : The cerebellar dentate nucleus, Springer, 1977. P. Brodal : Central nervous system, Oxford, 2006. Gray s Anatomy, Longman, 1973

REFERENCES : V. Chan-Palay: The cerebellar dentate nucleus, Springer, 1977. Gray s Anatomy, Longman, 1973. P.Brodal : Human nervous systém, Oxford, 2006.

Cajal 1911

Image266.x4 synapto